Infection-induced urinary stones are chronic, morbid, recurrent disease process that are recalcitrant to traditional medical management. Experimental and clinical investigations have shown that the bacterial enzyme urease is the primary biochemical mediator of this calculogenesis via the hydrolysis of endogenous urea. Ureolysis may also contribute to the virulence and invasiveness of some bacterial species. Phase III clinical trials are in progress that evaluate the safety and efficacy of Acetohydroxamic Acid (AHA), a well-established inhibitor of urease. To date, systemic treatment with AHA seems to be both safe and effective in inhibiting ureolysis in patients who harbor a chronic urea-splitting urinary infection. A subclinical hemolytic reaction has occurred in approximately 15% of patients, and superficial phlebitis has occurred in approximately 10% of the 100 or so patients who have been treated. Documentation of stone growth/recurrence/dissolution is in progress.